Source code for

from pyteal import (
from pyteal.types import require_type

[docs]class BoxMapping: """Mapping provides an abstraction to store some typed data in a box keyed with a typed key"""
[docs] def __init__( self, key_type: type[abi.BaseType], value_type: type[abi.BaseType], prefix: Expr | None = None, ): """Initialize a Mapping object with details about storage Args: key_type: The type that will be used for the key. This type *MUST* encode to a byte string of < 64 bytes or it will fail at runtime. value_type: The type to be stored in the box. prefix (Optional): An optional argument to prefix the key, providing a name space in order to avoid collisions with other mappings using the same keys """ self._key_type = key_type self._key_type_spec = abi.type_spec_from_annotation(key_type) self._value_type = value_type self._value_type_spec = abi.type_spec_from_annotation(value_type) if prefix is not None: require_type(prefix, TealType.bytes) self.prefix = prefix
def _prefix_key(self, key: Expr) -> Expr: if self.prefix is not None: return Concat(self.prefix, key) return key
[docs] class Element: """Container type for a specific box key and type"""
[docs] def __init__(self, key: Expr, value_type: type[abi.BaseType]): require_type(key, TealType.bytes) self.key = key self._value_type = value_type
[docs] def exists(self) -> Expr: """check to see if a box with this key exists.""" return Seq(maybe := BoxLen(self.key), maybe.hasValue())
[docs] def store_into(self, val: abi.BaseType) -> Expr: """decode the bytes from this box into an abi type. Args: val: An instance of the type to be populated with the bytes from the box """ return val.decode(self.get())
[docs] def get(self) -> Expr: """get the bytes from this box.""" return Seq( maybe := BoxGet(self.key), Assert(maybe.hasValue()), maybe.value() )
[docs] def set(self, val: abi.BaseType | Expr) -> Expr: """overwrites the contents of the box with the provided value. Args: val: An instance of the type or an Expr that evaluates to bytes """ match val: case abi.BaseType(): if not isinstance(val, self._value_type): raise TealTypeError(val.__class__, self._value_type) bytes_val = val.encode() case Expr(): require_type(val, TealType.bytes) bytes_val = val case _: raise TealTypeError(type(val), Expr | abi.BaseType) return Seq( Pop(BoxDelete(self.key)), BoxPut(self.key, bytes_val), )
[docs] def delete(self) -> Expr: """delete the box at this key""" return BoxDelete(self.key)
def __getitem__(self, key: abi.BaseType | Expr) -> Element: match key: case abi.BaseType(): if key.type_spec() != self._key_type_spec: raise TealTypeError(key.type_spec(), self._key_type_spec) key = key.encode() case Expr(): require_type(key, TealType.bytes) case _: raise TealTypeError(type(key), Expr | abi.BaseType) return self.Element(self._prefix_key(key), self._value_type)